By Lisa Broadt Nearly every day since September, Tenino’s wastewater treatment plant has seen its pH level drop, and no one knows why.
But it’s a mystery that needs to be solved soon. The pH change eventually will damage the plant, says Tenino Public Works director Dave Defoe.
Defoe said bacteria help keep the plant in balance.
“(The change) is hard on the bacteria,” he said.
Over the past six months, Tenino has seen its pH readings drop as low as 3.5; an ideal reading on the 14-point scale is a 7. Readings below 7 are considered acidic.
A wide range of culprits could be the cause. In large quantities, substances from black coffee to lemon juice to battery acid all could affect the pH balance.
Defoe said that whatever it is, there’s a lot of it.
“They might be dumping it down the sink or the toilet, but it’s a significant amount and it happens quite often,” he said.
Defoe said police do not believe criminal activity, such as a methamphetamine lab, is to blame.
Local schools said they have not changed cleaning products or made any other significant changes.
“Short of going to every tank in town, taking the lid off and getting a sample,” Defoe said, “I don’t know.”
He said he hopes media coverage will alert residents to the problem. For more information, contact Tenino Public Works at 360-264-2368.